1. Field of the Invention
This invention relates to a magnetic recording or reproducing apparatus for performing the magnetic recording or reproducing operation of information on, for example, a magnetic tape, and more particularly, to a magnetic recording or reproducing apparatus having a tape loading mechanism for performing a so-called loading operation which loads a magnetic tape on a magnetic head unit and a so-called unloading operation which withdraws the magnetic tape from the magnetic head unit.
2. Description of the Prior Art
There exists a VCR (video cassette recorder) which is provided with a tape loading mechanism for performing a loading operation which draws a magnetic tape out of a magnetic-tape cassette mounted in the VCR and loads the magnetic tape by winding it around a drum along the outer circumference of which magnetic heads rotate. This VCR also performs an unloading operation which takes up the magnetic tape wound around the drum and withdraws the magnetic tape within the cassette. Various methods have been proposed as the tape loading mechanism for the VCR. A method has, for example, been adopted which performs the loading and unloading operations by moving a plurality of magnetictape guide members by rotatably driving two rings, each ring separately supporting a corresponding guide member.
In conventional configurations for the tape loading mechanism of this kind, the magnetic tape guide members moved to loading completion positions by the rotation of the rings during the loading operation are positioned by being pressed against locating members by the energizing force of springs. The springs for this locating operation are mounted on the respective rings. To put it concretely, slide plates are slidably provided on the respective rings, the magnetic tape guide members are mounted on the respective slide plates, and the slide plates are energized by the respective springs mounted on the rings.
FIG. 1 shows a typical tape loading mechanism using such a method, and shows the neighborhood of the above-described rings as a principal part of the mechanism. In FIG. 1, there is shown a main chassis 101 of the apparatus. Rings 106 and 107 as described above are rotatably supported on the chassis 101 by a common support member 108, and are provided one above the other. During the loading and unloading operations, the ring 106 is rotatably driven by a motor (not shown), the rotating driving force of the ring 106 is transmitted to the ring 107 via gears 110 and 111 rotate the ring 107. Springs 121 and 112 for energizing the magnetic tape guide members in order to position the guide members as described before are mounted to the rings 106 and 107, respectively, to energize slide plates (not shown).
In the structure as described above, however, since the slide plates and springs are mounted on the respective rings, space is needed in the direction of the thickness of the device. Especially when the winding angle of the magnetic tape around the drum becomes larger as the size of the VCR becomes smaller, the springs 112 and 121 are necessarily superposed one above another, as shown in FIG. 1. Hence, there is the disadvantage that a further space is needed in the direction of the thickness of the device and this is an obstacle when it is intended to provide a thin apparatus.
Furthermore, if the springs 112 and 121 are separated from each other so that they are not superposed one above another, the springs 121 and 112 rotate in accordance with the rotation of the rings 106 and 107. Hence, there is the disadvantage that a two-dimensionally large space is needed and this is an obstacle when it is intended to provide a small apparatus.